Largest seed bank
Millennium Seed Bank Project
United Kingdom ()

The largest seed bank is the Millennium Seed Bank Project, housed at the Wellcome Trust Millennium Building at Wakehurst, West Sussex, UK, which had more than 2.4 billion seeds, representing around 40,000 species, collected as of March 2021. The seeds are stored in underground frozen vaults and are part of an international conservation project, managed by Royal Botanic Gardens, Kew (UK), with the aim of insuring thousands of species against possible extinction. In April 2007, the project banked its billionth seed, a type of African bamboo called Oxytenanthera abyssinica.

Two out of every five plant species are currently at risk of extinction. By preserving samples in climate-controlled, sub-zero vaults underground, and working in partnership with similar projects worldwide, the Millennium Seed Bank hopes to provide a safe haven for endangered plants. These can then be germinated for later reintroduction in the wild, or studied for future foodstuffs or medicines. Seeds from nearly all the UK's native plant species are stored here.